36 results on '"A. N. Vantyghem"'
Search Results
2. A Quick Look at the 3 GHz Radio Sky. II. Hunting for DRAGNs in the VLA Sky Survey
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Yjan A. Gordon, Lawrence Rudnick, Heinz Andernach, Leah K. Morabito, Christopher P. O’Dea, Kaylan-Marie Achong, Stefi A. Baum, Caryelis Bayona-Figueroa, Eric J. Hooper, Beatriz Mingo, Melissa E. Morris, and Adrian N. Vantyghem
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Radio astronomy ,Radio galaxies ,Giant radio galaxies ,Extragalactic radio sources ,Active galactic nuclei ,Astrophysics ,QB460-466 - Abstract
Active galactic nuclei (AGNs) can often be identified in radio images as two lobes, sometimes connected to a core by a radio jet. This multicomponent morphology unfortunately creates difficulties for source finders, leading to components that are (a) separate parts of a wider whole, and (b) offset from the multiwavelength cross identification of the host galaxy. In this work we define an algorithm, DRAGN hunter , for identifying double radio sources associated with AGNs (DRAGNs) from component catalog data in the first epoch Quick Look images of the high-resolution (≈3″ beam size) Very Large Array Sky Survey (VLASS). We use DRAGN hunter to construct a catalog of >17,000 DRAGNs in VLASS for which contamination from spurious sources is estimated at ≈11%. A “high-fidelity” sample consisting of 90% of our catalog is identified for which contamination is
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- 2023
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3. Constraining the AGN duty cycle in the cool-core cluster MS 0735.6+7421 with LOFAR data
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Myriam Gitti, Jeremy J. Harwood, A. N. Vantyghem, Alastair C. Edge, Annalisa Bonafede, E. Bonnassieux, Nadia Biava, Marisa Brienza, C. J. Riseley, Biava N., Brienza M., Bonafede A., Gitti M., Bonnassieux E., Harwood J., Edge A.C., Riseley C.J., and Vantyghem A.
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Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,010308 nuclear & particles physics ,Galaxies: clusters: individual: MS 0735.6+7421 ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,LOFAR ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Galaxies: jet ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Radio continuum: galaxies ,Core (optical fiber) ,Space and Planetary Science ,Duty cycle ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Cluster (physics) ,Astrophysics - High Energy Astrophysical Phenomena ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
MS 0735.6+7421 is a galaxy cluster which hosts a central radio galaxy with a very steep spectrum, produced by one of the most powerful known jetted active galactic nuclei (AGN). The radio plasma, ejected at nearly light speed from the central AGN, have displaced the intra-cluster medium, leaving two pairs of cavities observable in the X-ray, associated to two different outbursts, and have distributed energy to the surrounding medium. In this work we have performed for the first time a detailed, high-resolution spectral study of the source at radio frequencies and investigated its duty cycle to be compared with previous X-ray estimates. We have used new observations at 144 MHz produced with the LOw Frequency ARray (LOFAR) together with archival data at higher frequencies. At LOFAR frequency, the source presents two large outer radio lobes, wider than at higher frequencies, and a smaller Intermediate lobe located south-west of the core. A new inspection of X-ray data, allowed us to identify an intermediate cavity, associated with that lobe, indicating the presence of a further phase of jet activity. The radio lobes have a steep spectrum even at LOFAR frequencies, reaching $\alpha_{144}^{610}=2.9$ in the outer lobes and $\alpha_{144}^{610}=2.1$ in the Intermediate lobe. Fitting the lobe spectra using a single injection model of particle ageing, we derived a total age of the source between 170 and 106 Myr, in agreement with the buoyancy and sound crossing time-scales derived from X-ray data. We then reconstructed the duty cycle of the source. There were three phases of jet activity, with the AGN being active for most of the time with only brief quiescent phases, ensuring the repeated heating of the central gas. Finally, energetic estimates revealed that a source of additional pressure support must be present to sustain the bubbles against the pressure of the external medium., Comment: 18 pages, 12 figures; accepted for publication in A&A
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- 2021
4. A Massive, Clumpy Molecular Gas Distribution and Displaced AGN in Zw 3146
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Francoise Combes, Paul Nulsen, Michael McDonald, H. R. Russell, A. N. Vantyghem, P. Salomé, Stefi A. Baum, Brian R. McNamara, Alastair C. Edge, Andrew C. Fabian, C. P. O'Dea, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)
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Active galactic nucleus ,010504 meteorology & atmospheric sciences ,Astrophysics::High Energy Astrophysical Phenomena ,Continuum (design consultancy) ,FOS: Physical sciences ,Galaxy clusters ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Submillimeter Array ,Intracluster medium ,0103 physical sciences ,Brightest cluster galaxy ,010303 astronomy & astrophysics ,Galaxy kinematics ,Galaxy cluster ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,[PHYS]Physics [physics] ,Physics ,Molecular gas ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Black hole ,Brightest cluster galaxies ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Active galaxies ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
We present a recent ALMA observation of the CO(1-0) line emission in the central galaxy of the Zw 3146 galaxy cluster ($z=0.2906$). We also present updated X-ray cavity measurements from archival Chandra observations. The $5\times 10^{10}\,M_{\odot}$ supply of molecular gas, which is confined to the central 4 kpc, is marginally resolved into three extensions that are reminiscent of the filaments observed in similar systems. No velocity structure that would be indicative of ordered motion is observed. The three molecular extensions all trail X-ray cavities, and are potentially formed from the condensation of intracluster gas lifted in the wakes of the rising bubbles. Many cycles of feedback would be require to account for the entire molecular gas reservoir. The molecular gas and continuum source are mutually offset by 2.6 kpc, with no detected line emission coincident with the continuum source. It is the molecular gas, not the continuum source, that lies at the gravitational center of the brightest cluster galaxy. As the brightest cluster galaxy contains possible tidal features, the displaced continuum source may correspond to the nucleus of a merging galaxy. We also discuss the possibility that a gravitational wave recoil following a black hole merger may account for the displacement., Accepted to ApJ. 12 pages, 9 figures
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- 2021
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5. Precision measurement of the nuclear polarization in laser-cooled, optically pumped 37K
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B Fenker, J A Behr, D Melconian, R M A Anderson, M Anholm, D Ashery, R S Behling, I Cohen, I Craiciu, J M Donohue, C Farfan, D Friesen, A Gorelov, J McNeil, M Mehlman, H Norton, K Olchanski, S Smale, O Thériault, A N Vantyghem, and C L Warner
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Beta-decay ,fundamental symmetries ,optical pumping ,atom trapping ,parity violation ,Science ,Physics ,QC1-999 - Abstract
We report a measurement of the nuclear polarization of laser-cooled, optically pumped ^37 K atoms which will allow us to precisely measure angular correlation parameters in the ${\beta }^{+}$ -decay of the same atoms. These results will be used to test the V − A framework of the weak interaction at high precision. At the Triumf neutral atom trap ( Trinat ), a magneto-optical trap confines and cools neutral ^37 K atoms and optical pumping spin-polarizes them. We monitor the nuclear polarization of the same atoms that are decaying in situ by photoionizing a small fraction of the partially polarized atoms and then use the standard optical Bloch equations to model their population distribution. We obtain an average nuclear polarization of $\bar{P}=0.9913\pm 0.0009$ , which is significantly more precise than previous measurements with this technique. Since our current measurement of the β -asymmetry has $0.2 \% $ statistical uncertainty, the polarization measurement reported here will not limit its overall uncertainty. This result also demonstrates the capability to measure the polarization to $\lt 0.1 \% $ , allowing for a measurement of angular correlation parameters to this level of precision, which would be competitive in searches for new physics.
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- 2016
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6. Thermally Unstable Cooling Stimulated by Uplift: The Spoiler Clusters
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Alastair C. Edge, Paul Nulsen, Michel J. P. Gingras, M. T. Hogan, Iu. V. Babyk, Michael McDonald, A. N. Vantyghem, P. D. Tamhane, Andrew C. Fabian, Brian R. McNamara, Helen Russell, and Connor Martz
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Physics ,010504 meteorology & atmospheric sciences ,Star formation ,Bubble ,Molecular cloud ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Cooling time ,Galaxy ,Spoiler ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Galaxy cluster ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences - Abstract
We analyzed Chandra X-ray observations of five galaxy clusters whose atmospheric cooling times, entropy parameters, and cooling time to free-fall time ratios within the central galaxies lie below 1 Gyr, below 30 keV cm^2, and between 20 < tcool/tff < 50, respectively. These thermodynamic properties are commonly associated with molecular clouds, bright H-alpha emission, and star formation in central galaxies. However, none of these clusters have detectable H-alpha indicated in the ACCEPT database, nor do they have significant star formation rates or detectable molecular gas. Among these, only RBS0533 has a detectable radio/X-ray bubble which are commonly observed in cooling atmospheres. Signatures of uplifted, high metallicity atmospheric gas are absent. Despite its prominent X-ray bubble, RBS0533 lacks significant levels of molecular gas. Cold gas is absent at appreciable levels in these systems perhaps because their radio sources have failed to lift low entropy atmospheric gas to an altitude where the ratio of the cooling time to the free-fall time falls below unity., Accepted for publication in ApJ. The draft includes significant changes to the Introduction intended to better motivate this work by placing the problem in the context of current theoretical understanding of thermally unstable cooling. The abstract and conclusion were edited for clarity
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- 2020
7. A Quick Look at the 3 GHz Radio Sky. I. Source Statistics from the Very Large Array Sky Survey
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Samar Safi-Harb, Jean-Paul Bui, Heinz Andernach, Michelle M. Boyce, Yjan A. Gordon, Stefi A. Baum, Isabel Sander, Lawrence Rudnick, Mathew Dionyssiou, A. N. Vantyghem, and Christopher P. O'Dea
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Active galactic nucleus ,Radio galaxy ,media_common.quotation_subject ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Correlation function (quantum field theory) ,01 natural sciences ,0103 physical sciences ,Source counts ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,media_common ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,Spectral index ,010308 nuclear & particles physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,LOFAR ,Astrophysics - Astrophysics of Galaxies ,Space and Planetary Science ,Sky ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Instrumentation and Methods for Astrophysics ,Radio astronomy - Abstract
The Very Large Array Sky Survey (VLASS) is observing the entire sky north of $-40^{\circ}$ in the S-band ($23\,$mJy/beam and are often unreliable for fainter components. We use this catalog to perform statistical analyses of the $\nu \sim 3\,$GHz radio sky. Comparisons with the Faint Images of the Radio Sky at Twenty cm survey (FIRST) show the typical $1.4-3\,$GHz spectral index, $\alpha$, to be $\sim-0.71$. The radio color-color distribution of point and extended components is explored by matching with FIRST and the LOFAR Two Meter Sky Survey. We present the VLASS source counts, $dN/dS$, which are found to be consistent with previous observations at $1.4$ and $3\,$GHz. Resolution improvements over FIRST result in excess power in the VLASS two-point correlation function at angular scales $\lesssim 7''$, and in $18\,\%$ of active galactic nuclei associated with a single FIRST component being split into multi-component sources by VLASS., Comment: Accepted for publication in ApJS; 23 pages, 18 figures, 4 tables. Revised version includes new flux calibration (section 3.2) that results in VLASS fluxes being scaled by 15% in the presented analyses rather than the 10% used in the earlier version. Associated VLASS catalog data available at https://cirada.ca/catalogues
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- 2021
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8. Revealing a highly dynamic cluster core in Abell 1664 with Chandra
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Michael S. Calzadilla, Grant R. Tremblay, A. N. Vantyghem, J. B. Raymond Oonk, Stefi A. Baum, Alastair C. Edge, Francoise Combes, Helen Russell, Paul Nulsen, Megan Donahue, Brian R. McNamara, Christopher P. O'Dea, Andrew C. Fabian, Michael McDonald, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)
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galaxies: clusters: individual ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Active galactic nucleus ,galaxies: clusters: intracluster medium ,010504 meteorology & atmospheric sciences ,Metallicity ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Gravitational potential ,Intracluster medium ,0103 physical sciences ,Brightest cluster galaxy ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Physics ,Astronomy and Astrophysics ,Atacama Large Millimeter Array ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Cold front ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,X-rays: galaxies: clusters ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present new, deep (245 ks) Chandra observations of the galaxy cluster Abell 1664 ($z = 0.1283$). These images reveal rich structure, including elongation and accompanying compressions of the X-ray isophotes in the NE-SW direction, suggesting that the hot gas is sloshing in the gravitational potential. This sloshing has resulted in cold fronts, at distances of 55, 115 and 320 kpc from the cluster center. Our results indicate that the core of A1664 is highly disturbed, as the global metallicity and cooling time flatten at small radii, implying mixing on large scales. The central AGN appears to have recently undergone a mechanical outburst, as evidenced by our detection of cavities. These cavities are the X-ray manifestations of radio bubbles inflated by the AGN, and may explain the motion of cold molecular CO clouds previously observed with ALMA. The estimated mechanical power of the AGN, using the minimum energy required to inflate the cavities as a proxy, is $P_{\rm cav} = (1.1 \pm 1.0) \times 10^{44} $ erg s$^{-1}$, which may be enough to drive the molecular gas flows, and offset the cooling luminosity of the ICM, at $L_{\rm cool} = (1.90 \pm0.01)\times 10^{44}$ erg s$^{-1}$. This mechanical power is orders of magnitude higher than the measured upper limit on the X-ray luminosity of the central AGN, suggesting that its black hole may be extremely massive and/or radiatively inefficient. We map temperature variations on the same spatial scale as the molecular gas, and find that the most rapidly cooling gas is mostly coincident with the molecular gas reservoir centered on the BCG's systemic velocity observed with ALMA and may be fueling cold accretion onto the central black hole., Submitted to ApJ. 14 pages, 7 figures, 1 table, 1 appendix. Comments welcome!
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- 2019
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9. An Enormous Molecular Gas Flow in the RX J0821+0752 Galaxy Cluster
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Andrew C. Fabian, Paul Nulsen, Michael McDonald, Alastair C. Edge, Brian R. McNamara, Helen Russell, Francoise Combes, P. Salomé, A. N. Vantyghem, Department of Physics, University of Wales, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), and TRIUMF [Vancouver]
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Physics ,010504 meteorology & atmospheric sciences ,Astrophysics of Galaxies ,Astrophysics::High Energy Astrophysical Phenomena ,Galactic Center ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Galaxy ,Plume ,Protein filament ,[PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA] ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Intracluster medium ,0103 physical sciences ,Cluster (physics) ,010303 astronomy & astrophysics ,Galaxy cluster ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Line (formation) - Abstract
We present recent {\it Chandra} X-ray observations of the RXJ0821.0+0752 galaxy cluster in addition to ALMA observations of the CO(1-0) and CO(3-2) line emission tracing the molecular gas in its central galaxy. All of the CO line emission, originating from a $10^{10}\,M_{\odot}$ molecular gas reservoir, is located several kpc away from the nucleus of the central galaxy. The cold gas is concentrated into two main clumps surrounded by a diffuse envelope. They form a wide filament coincident with a plume of bright X-ray emission emanating from the cluster core. This plume encompasses a putative X-ray cavity that is only large enough to have uplifted a few percent of the molecular gas. Unlike other brightest cluster galaxies, stimulated cooling, where X-ray cavities lift low entropy cluster gas until it becomes thermally unstable, cannot have produced the observed gas reservoir. Instead, the molecular gas has likely formed as a result of sloshing motions in the intracluster medium induced by a nearby galaxy. Sloshing can emulate uplift by dislodging gas from the galactic center. This gas has the shortest cooling time, so will condense if disrupted for long enough., 10 pages, 5 figures, accepted to ApJ
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- 2019
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10. Driving massive molecular gas flows in central cluster galaxies with AGN feedback
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Alastair C. Edge, Francoise Combes, Brian R. McNamara, A. N. Vantyghem, Helen Russell, V. Olivares, M. Madar, Paul Nulsen, Andrew C. Fabian, P. Salomé, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), and Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,Active galactic nucleus ,galaxies: clusters: intracluster medium ,010308 nuclear & particles physics ,Molecular cloud ,galaxies: active ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,galaxies: jets ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Galaxy ,Protein filament ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Streamlines, streaklines, and pathlines ,Astrophysics - High Energy Astrophysical Phenomena ,galaxies: evolution ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
We present an analysis of new and archival ALMA observations of molecular gas in twelve central cluster galaxies. We examine emerging trends in molecular filament morphology and gas velocities to understand their origins. Molecular gas masses in these systems span $10^9-10^{11}\mathrm{M}_{\odot}$, far more than most gas-rich galaxies. ALMA images reveal a distribution of morphologies from filamentary to disk-dominated structures. Circumnuclear disks on kiloparsec scales appear rare. In most systems, half to nearly all of the molecular gas lies in filamentary structures with masses of a few $\times10^{8-10}\mathrm{M}_{\odot}$ that extend radially several to several tens of kpc. In nearly all cases the molecular gas velocities lie far below stellar velocity dispersions, indicating youth, transience or both. Filament bulk velocities lie far below the galaxy's escape and free-fall speeds indicating they are bound and being decelerated. Most extended molecular filaments surround or lie beneath radio bubbles inflated by the central AGN. Smooth velocity gradients found along the filaments are consistent with gas flowing along streamlines surrounding these bubbles. Evidence suggests most of the molecular clouds formed from low entropy X-ray gas that became thermally unstable and cooled when lifted by the buoyant bubbles. Uplifted gas will stall and fall back to the galaxy in a circulating flow. The distribution in morphologies from filament to disk-dominated sources therefore implies slowly evolving molecular structures driven by the episodic activity of the AGN., 20 pages, 21 figures, 4 tables, accepted to MNRAS
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- 2019
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11. Ubiquitous cold and massive filaments in cool core clusters
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Megan Donahue, Pierre Guillard, F. L. Polles, A. N. Vantyghem, Francoise Combes, Grant R. Tremblay, Yohan Dubois, Alastair C. Edge, Stephen Hamer, Matthew D. Lehnert, V. Olivares, Gary J. Ferland, Tom Rose, P. Salomé, Helen Russell, B. Godard, Rebecca E. A. Canning, Brian R. McNamara, Sébastien Peirani, G. Pineau des Forêts, R. S. Beckmann, A. C. Fabian, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), University of Oxford [Oxford], University of Michigan [Ann Arbor], University of Michigan System, Department of Physics, University of Wales, Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Collège de France - Chaire Galaxies et cosmologie, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Oxford, and ANR-16-CE31-0011,LYRICS,Le cycle du gaz autour des galaxies : origine et conditions physiques des flots de gaz froid(2016)
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Physics ,Nebula ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,010308 nuclear & particles physics ,Turbulence ,FOS: Physical sciences ,Astronomy and Astrophysics ,Escape velocity ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Submillimeter Array ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Gravitational potential ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Cluster (physics) ,Millimeter ,010303 astronomy & astrophysics ,ComputingMilieux_MISCELLANEOUS ,Astrophysics::Galaxy Astrophysics - Abstract
Multi-phase filamentary structures around Brightest Cluster Galaxies are likely a key step of AGN-feedback. We observed molecular gas in 3 cool cluster cores: Centaurus, Abell S1101, and RXJ1539.5 and gathered ALMA and MUSE data for 12 other clusters. Those observations show clumpy, massive and long, 3--25 kpc, molecular filaments, preferentially located around the radio bubbles inflated by the AGN (Active Galactic Nucleus). Two objects show nuclear molecular disks. The optical nebula is certainly tracing the warm envelopes of cold molecular filaments. Surprisingly, the radial profile of the H$\alpha$/CO flux ratio is roughly constant for most of the objects, suggesting that (i) between 1.2 to 7 times more cold gas could be present and (ii) local processes must be responsible for the excitation. Projected velocities are between 100--400 km s$^{-1}$, with disturbed kinematics and sometimes coherent gradients. This is likely due to the mixing in projection of several thin unresolved filaments. The velocity fields may be stirred by turbulence induced by bubbles, jets or merger-induced sloshing. Velocity and dispersions are low, below the escape velocity. Cold clouds should eventually fall back and fuel the AGN. We compare the filament's radial extent, r$_{fil}$, with the region where the X-ray gas can become thermally unstable. The filaments are always inside the low-entropy and short cooling time region, where t$_{cool}$/t$_{ff}$, Comment: 33 Pages, 17 Figures, submitted to A&A
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- 2019
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12. A relationship between halo mass, cooling, active galactic nuclei heating and the co-evolution of massive black holes
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Robert Main, Helen E Russell, A. N. Vantyghem, Paul Nulsen, and Brian R. McNamara
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Physics ,Active galactic nucleus ,Stellar mass ,010308 nuclear & particles physics ,Star formation ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Galaxy ,Black hole ,Space and Planetary Science ,0103 physical sciences ,Galaxy formation and evolution ,Halo ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Galaxy cluster - Abstract
We derive X-ray mass, luminosity, and temperature profiles for 45 galaxy clusters to explore relationships between halo mass, AGN feedback, and central cooling time. We find that radio--mechanical feedback power (referred to here as "AGN power") in central cluster galaxies correlates with halo mass as P$_{\rm mech}$ $\propto$ M$^{1.55\pm0.26}$, but only in halos with central atmospheric cooling times shorter than 1 Gyr. The trend of AGN power with halo mass is consistent with the scaling expected from a self-regulating AGN feedback loop, as well as with galaxy and central black hole co-evolution along the $M_{\rm BH} - \sigma$ relation. AGN power in clusters with central atmospheric cooling times longer than $\sim 1$ Gyr typically lies two orders of magnitude below those with shorter central cooling times. Galaxies centred in clusters with long central cooling times nevertheless experience ongoing and occasionally powerful AGN outbursts. We further investigate the impact of feedback on cluster scaling relations. We find $L-T$, and $M-T$ relations in clusters with direct evidence of feedback which are steeper than self-similar, but not atypical compared to previous studies of the full cluster population. While the gas mass rises, the stellar mass remains nearly constant with rising total mass, consistent with earlier studies. This trend is found regardless of central cooling time, implying tight regulation of star formation in central galaxies as their halos grew, and long-term balance between AGN heating and atmospheric cooling. Our scaling relations are presented in forms that can be incorporated easily into galaxy evolution models.
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- 2016
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13. A Catalog of Very Large Array Sky Survey Epoch 1 Quick Look Components, Sources, and Host Identifications
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Yjan A. Gordon, Stefi Baum, A. N. Vantyghem, Mathew Dionyssiou, H. Andernach, Michelle M. Boyce, Christopher P. O'Dea, Jean-Paul Bui, and Lawrence Rudnick
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Very large array ,Physics ,Epoch (reference date) ,Sky ,media_common.quotation_subject ,Astronomy ,General Medicine ,Host (network) ,Radio astronomy ,media_common - Published
- 2020
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14. A galaxy-scale fountain of cold molecular gas pumped by a black hole
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Timothy A. Davis, Elizabeth L. Blanton, A. N. Vantyghem, C. Megan Urry, Tracy E. Clarke, Esra Bulbul, Andrew C. Fabian, Philippe Salomé, Yuanyuan Su, Brian R. McNamara, Francoise Combes, Paul Nulsen, Megan Donahue, Laurence P. David, Stefi A. Baum, Nathaniel Kerman, Christine Jones, Ming Sun, Ralph P. Kraft, Massimo Gaspari, Grant R. Tremblay, Christopher P. O'Dea, Louise O. V. Edwards, Aurora Simionescu, Helen Russell, Alastair C. Edge, William R. Forman, Belinda Jane Wilkes, Yuan Li, Stephen Hamer, Scott W. Randall, G. Mark Voit, John ZuHone, Michael McDonald, J. B. Raymond Oonk, Bernd Husemann, Malcolm N. Bremer, Meredith Powell, Dominic Eggerman, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), CSA, Canadian Space Agency (CSA), University of Michigan [Ann Arbor], University of Michigan System, Institute for Computational Cosmology (ICC), Durham University, Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Institute of Astronomy [Cambridge], and University of Cambridge [UK] (CAM)
- Subjects
astro-ph.GA ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,0103 physical sciences ,Galaxy formation and evolution ,clusters: general [galaxies] ,Astrophysics::Solar and Stellar Astrophysics ,Brightest cluster galaxy ,010303 astronomy & astrophysics ,ComputingMilieux_MISCELLANEOUS ,Galaxy cluster ,Astrophysics::Galaxy Astrophysics ,QB ,[PHYS]Physics [physics] ,Physics ,Nebula ,Supermassive black hole ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Accretion (astrophysics) ,Black hole ,galaxies: clusters: general ,Space and Planetary Science ,galaxies: star formation ,Astrophysics of Galaxies (astro-ph.GA) ,clusters: individual (Abell 2597) [galaxies] ,galaxies: clusters: individual (Abell 2597) ,star formation [galaxies] ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
著者人数: 39名(所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): Simionescu, Aurora), Accepted: 2018-07-28, 資料番号: SA1180203000
- Published
- 2018
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15. The Origin of Molecular Clouds in Central Galaxies
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A. N. Vantyghem, Alastair C. Edge, F. A. Pulido, Paul Nulsen, Iu. V. Babyk, Brian R. McNamara, P. Salomé, M. T. Hogan, Helen Russell, Institute for Computational Cosmology (ICC), Durham University, SLAC National Accelerator Laboratory (SLAC), Stanford University, Dublin City University, Dublin 9, Ireland, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
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Physics ,[PHYS]Physics [physics] ,010308 nuclear & particles physics ,Star formation ,Molecular cloud ,FOS: Physical sciences ,Astronomy and Astrophysics ,Time ratio ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Cooling time ,Galaxy ,Uncorrelated ,13. Climate action ,Space and Planetary Science ,Thermal instability ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Narrow range ,Astrophysics::Earth and Planetary Astrophysics ,Atomic physics ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,ComputingMilieux_MISCELLANEOUS - Abstract
We present an analysis of 55 central galaxies in clusters and groups with molecular gas masses and star formation rates lying between $10^{8}-10^{11}\ M_{\odot}$ and $0.5-270$ $M_{\odot}\ yr^{-1}$, respectively. We have used Chandra observations to derive profiles of total mass and various thermodynamic variables. Molecular gas is detected only when the central cooling time or entropy index of the hot atmosphere falls below $\sim$1 Gyr or $\sim$35 keV cm$^2$, respectively, at a (resolved) radius of 10 kpc. This indicates that the molecular gas condensed from hot atmospheres surrounding the central galaxies. The depletion timescale of molecular gas due to star formation approaches 1 Gyr in most systems. Yet ALMA images of roughly a half dozen systems drawn from this sample suggest the molecular gas formed recently. We explore the origins of thermally unstable cooling by evaluating whether molecular gas becomes prevalent when the minimum of the cooling to free-fall time ratio ($t_{\rm cool}/t_{\rm ff}$) falls below $\sim10$. We find: 1) molecular gas-rich systems instead lie between $10 < min(t_{\rm cool}/t_{\rm ff}) < 25$, where $t_{\rm cool}/t_{\rm ff}=25$ corresponds approximately to cooling time and entropy thresholds $t_{\rm cool} \lesssim 1$ Gyr and 35 keV~cm$^2$, respectively, 2) $min(t_{\rm cool}/t_{\rm ff}$) is uncorrelated with molecular gas mass and jet power, and 3) the narrow range $10 < min(t_{\rm cool}/t_{\rm ff}) < 25$ can be explained by an observational selection effect. These results and the absence of isentropic cores in cluster atmospheres are in tension with "precipitation" models, particularly those that assume thermal instability ensues from linear density perturbations in hot atmospheres. Some and possibly all of the molecular gas may instead have condensed from atmospheric gas lifted outward either by buoyantly-rising X-ray bubbles or merger-induced gas motions., 18 pages, 10 figures, 5 tables, submitted to ApJ
- Published
- 2018
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16. The onset of thermally unstable cooling from the hot atmospheres of giant galaxies in clusters : constraints on feedback models
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Alastair C. Edge, Michael McDonald, M. T. Hogan, Helen Russell, Iu. V. Babyk, Brian R. McNamara, Paul Nulsen, F. A. Pulido, Robert Main, and A. N. Vantyghem
- Subjects
Physics ,Active galactic nucleus ,Isentropic process ,010308 nuclear & particles physics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Coupling (probability) ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Power law ,Galaxy ,Entropy (classical thermodynamics) ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Cluster (physics) ,Atomic physics ,010303 astronomy & astrophysics ,Galaxy cluster - Abstract
We present accurate mass and thermodynamic profiles for a sample of 56 galaxy clusters observed with the Chandra X-ray Observatory. We investigate the effects of local gravitational acceleration in central cluster galaxies, and we explore the role of the local free-fall time (t$_{\rm ff}$) in thermally unstable cooling. We find that the local cooling time (t$_{\rm cool}$) is as effective an indicator of cold gas, traced through its nebular emission, as the ratio of t$_{\rm cool}$/t$_{\rm ff}$. Therefore, t$_{\rm cool}$ alone apparently governs the onset of thermally unstable cooling in hot atmospheres. The location of the minimum t$_{\rm cool}$/t$_{\rm ff}$, a thermodynamic parameter that simulations suggest may be key in driving thermal instability, is unresolved in most systems. As a consequence, selection effects bias the value and reduce the observed range in measured t$_{\rm cool}$/t$_{\rm ff}$ minima. The entropy profiles of cool-core clusters are characterized by broken power-laws down to our resolution limit, with no indication of isentropic cores. We show, for the first time, that mass isothermality and the $K \propto r^{2/3}$ entropy profile slope imply a floor in t$_{\rm cool}$/t$_{\rm ff}$ profiles within central galaxies. No significant departures of t$_{\rm cool}$/t$_{\rm ff}$ below 10 are found, which is inconsistent with many recent feedback models. The inner densities and cooling times of cluster atmospheres are resilient to change in response to powerful AGN activity, suggesting that the energy coupling between AGN heating and atmospheric gas is gentler than most models predict., Comment: 16 pages (+ 8 pages of Appendices), 13 figures, 2 tables (in Appendices). Submitted to ApJ
- Published
- 2017
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17. A 13 CO Detection in a Brightest Cluster Galaxy
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Alastair C. Edge, P. Salomé, M. T. Hogan, Francoise Combes, Andrew C. Fabian, Paul Nulsen, A. N. Vantyghem, Helen Russell, Brian R. McNamara, Michael McDonald, Department of Physics, University of Wales, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Collège de France - Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), École normale supérieure - Paris (ENS Paris), and Chaire Galaxies et cosmologie
- Subjects
Physics ,[PHYS]Physics [physics] ,010308 nuclear & particles physics ,FOS: Physical sciences ,Astronomy ,Astronomy and Astrophysics ,Space (mathematics) ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Brightest cluster galaxy ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,010303 astronomy & astrophysics ,ComputingMilieux_MISCELLANEOUS - Abstract
We present ALMA Cycle 4 observations of CO(1-0), CO(3-2), and $^{13}$CO(3-2) line emission in the brightest cluster galaxy of RXJ0821+0752. This is one of the first detections of $^{13}$CO line emission in a galaxy cluster. Half of the CO(3-2) line emission originates from two clumps of molecular gas that are spatially offset from the galactic center. These clumps are surrounded by diffuse emission that extends $8~{\rm kpc}$ in length. The detected $^{13}$CO emission is confined entirely to the two bright clumps, with any emission outside of this region lying below our detection threshold. Two distinct velocity components with similar integrated fluxes are detected in the $^{12}$CO spectra. The narrower component ($60~{\rm km}~{\rm s}^{-1}$ FWHM) is consistent in both velocity centroid and linewidth with $^{13}$CO(3-2) emission, while the broader ($130-160~{\rm km}~{\rm s}^{-1}$), slightly blueshifted wing has no associated $^{13}$CO(3-2) emission. A simple local thermodynamic model indicates that the $^{13}$CO emission traces $2.1\times 10^{9}~{\rm M}_\odot$ of molecular gas. Isolating the $^{12}$CO velocity component that accompanies the $^{13}$CO emission yields a CO-to-H$_2$ conversion factor of $\alpha_{\rm CO}=2.3~{\rm M}_{\odot}~({\rm K~km~s^{-1}})^{-1}$, which is a factor of two lower than the Galactic value. Adopting the Galactic CO-to-H$_2$ conversion factor in brightest cluster galaxies may therefore overestimate their molecular gas masses by a factor of two. This is within the object-to-object scatter from extragalactic sources, so calibrations in a larger sample of clusters are necessary in order to confirm a sub-Galactic conversion factor., Comment: 11 pages, 5 figures, accepted by ApJ
- Published
- 2017
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18. Mass distribution in galaxy cluster cores
- Author
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M. T. Hogan, Alastair C. Edge, Helen Russell, Paul Nulsen, Brian R. McNamara, A. N. Vantyghem, Robert Main, and F. A. Pulido
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Physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Mass distribution ,010308 nuclear & particles physics ,Dark matter ,FOS: Physical sciences ,Astronomy and Astrophysics ,Small sample ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Cluster (physics) ,Entropy (information theory) ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Mass budget ,Galaxy cluster ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Many processes within galaxy clusters, such as those believed to govern the onset of thermally unstable cooling and AGN feedback, are dependent upon local dynamical timescales. However, accurately mapping the mass distribution within individual clusters is challenging, particularly towards cluster centres where the total mass budget has substantial radially-dependent contributions from the stellar, gas, and dark matter components. In this paper we use a small sample of galaxy clusters with deep Chandra observations and good ancillary tracers of their gravitating mass at both large and small radii to develop a method for determining mass profiles that span a wide radial range and extend down into the central galaxy. We also consider potential observational pitfalls in understanding cooling in hot cluster atmospheres, and find tentative evidence for a relationship between the radial extent of cooling X-ray gas and nebular H-alpha emission in cool core clusters. Amongst this small sample we find no support for the existence of a central 'entropy floor', with the entropy profiles following a power-law profile down to our resolution limit., 15 pages, 9 figures, 2 tables. Submitted to ApJ
- Published
- 2017
19. Close entrainment of massive molecular gas flows by radio bubbles in the central galaxy of Abell 1795
- Author
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M. T. Hogan, Helen Russell, Paul Nulsen, P. Salomé, Alastair C. Edge, Andrew C. Fabian, Brian R. McNamara, Grant R. Tremblay, Francoise Combes, A. N. Vantyghem, Michael McDonald, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Collège de France (CdF), Fabian, Andrew [0000-0002-9378-4072], Apollo - University of Cambridge Repository, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique ( LERMA ), École normale supérieure - Paris ( ENS Paris ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université de Cergy Pontoise ( UCP ), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique ( CNRS ), Collège de France ( CdF ), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Chaire Galaxies et cosmologie, and Collège de France (CdF (institution))
- Subjects
cooling flows ,Active galactic nucleus ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Bubble ,[ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph] ,Astrophysics::High Energy Astrophysical Phenomena ,galaxies: active ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Protein filament ,X-shaped radio galaxy ,0103 physical sciences ,galaxies: clusters: Abell 1795 ,010306 general physics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Physics ,galaxies: clusters: individual: Abell 1795 ,Star formation ,Velocity gradient ,Molecular cloud ,Astronomy ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,galaxies: evolution ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present new ALMA observations tracing the morphology and velocity structure of the molecular gas in the central galaxy of the cluster Abell 1795. The molecular gas lies in two filaments that extend 5 - 7 kpc to the N and S from the nucleus and project exclusively around the outer edges of two inner radio bubbles. Radio jets launched by the central AGN have inflated bubbles filled with relativistic plasma into the hot atmosphere surrounding the central galaxy. The N filament has a smoothly increasing velocity gradient along its length from the central galaxy's systemic velocity at the nucleus to -370 km/s, the average velocity of the surrounding galaxies, at the furthest extent. The S filament has a similarly smooth but shallower velocity gradient and appears to have partially collapsed in a burst of star formation. The close spatial association with the radio lobes, together with the ordered velocity gradients and narrow velocity dispersions, show that the molecular filaments are gas flows entrained by the expanding radio bubbles. Assuming a Galactic $X_{\mathrm{CO}}$ factor, the total molecular gas mass is $3.2\pm0.2\times10^{9}$M$_{\odot}$. More than half lies above the N radio bubble. Lifting the molecular clouds appears to require an infeasibly efficient coupling between the molecular gas and the radio bubble. The energy required also exceeds the mechanical power of the N radio bubble by a factor of two. Stimulated feedback, where the radio bubbles lift low entropy X-ray gas that becomes thermally unstable and rapidly cools in situ, provides a plausible model. Multiple generations of radio bubbles are required to lift this substantial gas mass. The close morphological association then indicates that the cold gas either moulds the newly expanding bubbles or is itself pushed aside and shaped as they inflate., 14 pages, 9 figures, accepted to MNRAS
- Published
- 2017
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20. Radiative efficiency, variability and Bondi accretion on to massive black holes: the transition from radio AGN to quasars in brightest cluster galaxies
- Author
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M. T. Hogan, A. N. Vantyghem, R. A. Main, Brian R. McNamara, Alastair C. Edge, and Helen Russell
- Subjects
Accretion ,Active galactic nucleus ,active [Galaxies] ,Bondi accretion ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Intermediate polar ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Physics ,Supermassive black hole ,010308 nuclear & particles physics ,Astronomy ,Astronomy and Astrophysics ,Quasar ,Galaxy ,Accretion (astrophysics) ,13. Climate action ,Space and Planetary Science ,Spectral energy distribution ,jets [Galaxies] ,galaxies: clusters [X-rays] ,Astrophysics::Earth and Planetary Astrophysics ,Accretion discs - Abstract
We examine unresolved nuclear X-ray sources in 57 brightest cluster galaxies to study the relationship between nuclear X-ray emission and accretion on to supermassive black holes. The majority of the clusters in our sample have prominent X-ray cavities embedded in the surrounding hot atmospheres, which we use to estimate mean jet power and average accretion rate on to the supermassive black holes over the past several hundred Myr. We find that roughly half of the sample have detectable nuclear X-ray emission. The nuclear X-ray luminosity is correlated with average accretion rate determined using X-ray cavities, which is consistent with the hypothesis that nuclear X-ray emission traces ongoing accretion. The results imply that jets in systems that have experienced recent active galactic nucleus (AGN) outbursts, in the last ∼107 yr, are ‘on’ at least half of the time. Nuclear X-ray sources become more luminous with respect to the mechanical jet power as the mean accretion rate rises. We show that nuclear radiation exceeds the jet power when the mean accretion rate rises above a few per cent of the Eddington rate, or a power output of ∼1045ergs−1, where the AGN apparently transitions to a quasar. The nuclear X-ray emission from three objects (A2052, Hydra A, M84) varies by factors of 2–10 on time-scales of 6 months to 10 years. If variability at this level is a common phenomenon, it can account for much of the scatter in the relationship between mean accretion rate and nuclear X-ray luminosity. We find no significant change in the spectral energy distribution as a function of luminosity in the variable objects. The nuclear X-ray luminosity is consistent with emission from either a jet, an advection-dominated accretion flow, or a combination of the two, although other origins are possible. We also consider the longstanding problem of whether jets are powered by the accretion of cold circumnuclear gas or nearly spherical inflows of hot keV gas. For a subset of 13 nearby systems in our sample, we re-examine the relationship between the jet power and the Bondi accretion rate. The results indicate weaker evidence for a trend between Bondi accretion and jet power, due to uncertainties in the cavity volumes and gas densities at the Bondi radius. We suggest that cold gas fuelling could be a likely source of accretion power in these objects; however, we cannot rule out Bondi accretion, which could play a significant role in low-power jets.
- Published
- 2013
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21. Molecular gas along a bright H$\alpha$ filament in 2A 0335+096 revealed by ALMA
- Author
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Robert Main, P. E. J. Nulsen, Jeremy S. Sanders, Francoise Combes, A. C. Edge, Christopher P. O'Dea, Stefi A. Baum, J. B. R. Oonk, A. C. Fabian, P. Salomé, I. J. Parrish, Brian R. McNamara, A. N. Vantyghem, Grant R. Tremblay, Norm Murray, Megan Donahue, M. T. Hogan, G. M. Voit, Robert W. O'Connell, Helen Russell, Fabian, Andrew [0000-0002-9378-4072], Apollo - University of Cambridge Repository, SLAC National Accelerator Laboratory (SLAC), Stanford University, Department of Physics, University of Wales, Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), University of Michigan [Ann Arbor], University of Michigan System, École normale supérieure - Paris (ENS-PSL), and Collège de France - Chaire Galaxies et cosmologie
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,galaxies: active ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Protein filament ,Intracluster medium ,0103 physical sciences ,galaxies: clusters: individual (2A 0335+096) ,Astrophysics::Solar and Stellar Astrophysics ,Brightest cluster galaxy ,010303 astronomy & astrophysics ,Galaxy cluster ,ComputingMilieux_MISCELLANEOUS ,Astrophysics::Galaxy Astrophysics ,galaxies: kinematics and dynamics ,Physics ,[PHYS]Physics [physics] ,Nebula ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Redshift ,Galaxy ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,H-alpha ,Astrophysics::Earth and Planetary Astrophysics ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,galaxies: ISM - Abstract
We present ALMA CO(1-0) and CO(3-2) observations of the brightest cluster galaxy (BCG) in the 2A 0335+096 galaxy cluster (z = 0.0346). The total molecular gas mass of (1.13+/-0.15) x 10^9 M_sun is divided into two components: a nuclear region and a 7 kpc long dusty filament. The central molecular gas component accounts for (3.2+/-0.4) x 10^8 M_sun of the total supply of cold gas. Instead of forming a rotationally-supported ring or disk, it is composed of two distinct, blueshifted clumps south of the nucleus and a series of low-significance redshifted clumps extending toward a nearby companion galaxy. The velocity of the redshifted clouds increases with radius to a value consistent with the companion galaxy, suggesting that an interaction between these galaxies, 21 pages, 14 figures, accepted to ApJ
- Published
- 2016
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22. ALMA observations of cold molecular gas filaments trailing rising radio bubbles in PKS 0745−191
- Author
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G. M. Voit, Robert Main, A. C. Fabian, A. N. Vantyghem, Alastair C. Edge, I. J. Parrish, Christopher P. O'Dea, Brian R. McNamara, Stefi A. Baum, J. B. R. Oonk, Robert W. O'Connell, Helen Russell, Norm Murray, Grant R. Tremblay, Paul Nulsen, Megan Donahue, Francoise Combes, P. Salomé, Jeremy S. Sanders, Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Department of Physics, University of Wales, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), University of Michigan [Ann Arbor], University of Michigan System, École normale supérieure - Paris (ENS-PSL), and Collège de France - Chaire Galaxies et cosmologie
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Protein filament ,0103 physical sciences ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,ComputingMilieux_MISCELLANEOUS ,Physics ,[PHYS]Physics [physics] ,Spiral galaxy ,010308 nuclear & particles physics ,Molecular cloud ,Velocity dispersion ,Astronomy ,Astronomy and Astrophysics ,Type-cD galaxy ,Astrophysics - Astrophysics of Galaxies ,Dust lane ,Galaxy ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Dark galaxy ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
We present ALMA observations of the CO(1-0) and CO(3-2) line emission tracing filaments of cold molecular gas in the central galaxy of the cluster PKS0745-191. The total molecular gas mass of 4.6 +/- 0.3 x 10^9 solar masses, assuming a Galactic X_{CO} factor, is divided roughly equally between three filaments each extending radially 3-5 kpc from the galaxy centre. The emission peak is located in the SE filament roughly 1 arcsec (2 kpc) from the nucleus. The velocities of the molecular clouds in the filaments are low, lying within +/-100 km/s of the galaxy's systemic velocity. Their FWHMs are less than 150 km/s, which is significantly below the stellar velocity dispersion. Although the molecular mass of each filament is comparable to a rich spiral galaxy, such low velocities show that the filaments are transient and the clouds would disperse on, 16 pages, 10 figures, accepted by MNRAS
- Published
- 2016
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23. Precision measurement of the nuclear polarization in laser-cooled, optically pumped $^{37}\mathrm{K}$
- Author
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B. Fenker, C. Farfan, Daniel Ashery, H. Norton, J M Donohue, D. Friesen, Melissa Anholm, K. Olchanski, J McNeil, A. Gorelov, M. Mehlman, O. Theriault, A N Vantyghem, I. Craiciu, John Behr, I Cohen, Dan Melconian, R.M.A. Anderson, R. S. Behling, S. Smale, and C. L. Warner
- Subjects
Physics ,education.field_of_study ,Energetic neutral atom ,Atomic Physics (physics.atom-ph) ,010308 nuclear & particles physics ,Population ,FOS: Physical sciences ,General Physics and Astronomy ,Weak interaction ,Polarization (waves) ,Laser ,01 natural sciences ,Fundamental interaction ,law.invention ,Physics - Atomic Physics ,Optical pumping ,Bloch equations ,law ,0103 physical sciences ,Physics::Atomic Physics ,Nuclear Experiment (nucl-ex) ,Atomic physics ,010306 general physics ,education ,Nuclear Experiment - Abstract
We report a measurement of the nuclear polarization of laser-cooled, optically-pumped $^{37}\mathrm{K}$ atoms which will allow us to precisely measure angular correlation parameters in the beta-decay of the same atoms. These results will be used to test the $V-A$ framework of the weak interaction at high precision. At the TRIUMF Neutral Atom Trap (TRINAT), a magneto-optical trap (MOT) confines and cools neutral $^{37}\mathrm{K}$ atoms and optical pumping spin-polarizes them. We monitor the nuclear polarization of the same atoms that are decaying in situ by photoionizing a small fraction of the partially polarized atoms and then use the standard optical Bloch equations to model their population distribution. We obtain an average nuclear polarization of $P = 0.9913\pm0.0008$, which is significantly more precise than previous measurements with this technique. Since our current measurement of the beta-asymmetry has $0.2\%$ statistical uncertainty, the polarization measurement reported here will not limit its overall uncertainty. This result also demonstrates the capability to measure the polarization to $, 32 pages, 11 figures, submitted to New Journal of Physics
- Published
- 2016
24. Molecular Gas Filaments and Star-forming Knots Beneath an X-Ray Cavity in RXC J1504–0248
- Author
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Alastair C. Edge, Brian R. McNamara, Andrew C. Fabian, P. Salomé, Michael McDonald, Paul Nulsen, Helen Russell, A. N. Vantyghem, Francoise Combes, Institute for Computational Cosmology (ICC), Durham University, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Institute of Astronomy [Cambridge], and University of Cambridge [UK] (CAM)
- Subjects
[PHYS]Physics [physics] ,Physics ,Active galactic nucleus ,010308 nuclear & particles physics ,Star formation ,Galactic Center ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Galaxy ,Protein filament ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Cluster (physics) ,Emission spectrum ,Brightest cluster galaxy ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,010303 astronomy & astrophysics ,ComputingMilieux_MISCELLANEOUS ,Astrophysics::Galaxy Astrophysics - Abstract
We present recent ALMA observations of the CO(1-0) and CO(3-2) emission lines in the brightest cluster galaxy of RXCJ1504.1$-$0248, which is one of the most extreme cool core clusters known. The central galaxy contains $1.9\times 10^{10}~M_{\odot}$ of molecular gas. The molecular gas morphology is complex and disturbed, showing no evidence for a rotationally-supported structure in equilibrium. $80\%$ of the gas is situated within the central 5 kpc of the galactic center, while the remaining gas is located in a 20 kpc long filament. The cold gas has likely condensed out of the hot atmosphere. The filament is oriented along the edge of a putative X-ray cavity, suggesting that AGN activity has stimulated condensation. This is enegetically feasible, although the morphology is not as conclusive as systems whose molecular filaments trail directly behind buoyant radio bubbles. The velocity gradient along the filament is smooth and shallow. It is only consistent with free-fall if it lies within $20^{\circ}$ of the plane of the sky. The abundance of clusters with comparably low velocities suggests that the filament is not free-falling. Both the central and filamentary gas are coincident with bright UV emission from ongoing star formation. Star formation near the cluster core is consistent with the Kennicutt-Schmidt law. The filament exhibits increased star formation surface densities, possibly resulting from either the consumption of a finite molecular gas supply or spatial variations in the CO-to-H$_2$ conversion factor., 15 pages, 10 figures, accepted in ApJ
- Published
- 2018
- Full Text
- View/download PDF
25. A Universal Entropy Profile for the Hot Atmospheres of Galaxies and Clusters within R 2500
- Author
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A. N. Vantyghem, Helen Russell, F. A. Pulido, M. T. Hogan, Iu. V. Babyk, Brian R. McNamara, and Paul Nulsen
- Subjects
Physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,010308 nuclear & particles physics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Galaxy ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Statistical physics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present atmospheric gas entropy profiles for 40 early type galaxies and 110 clusters spanning several decades of halo mass, atmospheric gas mass, radio jet power, and galaxy type. We show that within $\sim 0.1R_{2500}$ the entropy profiles of low-mass systems, including ellipticals, brightest cluster galaxies, and spiral galaxies, scale approximately as $K\propto R^{2/3}$. Beyond $\sim 0.1R_{2500}$ entropy profiles are slightly shallower than the $K \propto R^{1.1}$ profile expected from gravitational collapse alone, indicating that heating by AGN feedback extends well beyond the central galaxy. We show that the $K\propto R^{2/3}$ entropy profile shape indicates that thermally unstable cooling is balanced by heating where the inner cooling and free-fall timescales approach a constant ratio. Hot atmospheres of elliptical galaxies have a higher rate of heating per gas particle compared to central cluster galaxies. This excess heating may explain why some central cluster galaxies are forming stars while most early-type galaxies have experienced no significant star formation for billions of years. We show that the entropy profiles of six lenticular and spiral galaxies follow the $R^{2/3}$ form. The continuity between central galaxies in clusters, giant ellipticals, and spirals suggests perhaps that processes heating the atmospheres of elliptical and brightest cluster galaxies are also active in spiral galaxies., Comment: 11 pages, 9 figures, 2 tables, Accepted for publication in The Astrophysical Journal
- Published
- 2018
- Full Text
- View/download PDF
26. X-Ray Scaling Relations of Early-type Galaxies
- Author
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Iu. V. Babyk, Brian R. McNamara, M. T. Hogan, F. A. Pulido, Alastair C. Edge, A. N. Vantyghem, Paul Nulsen, and Helen Russell
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Luminosity ,Gravitation ,Observatory ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,010306 general physics ,010303 astronomy & astrophysics ,Scaling ,Astrophysics::Galaxy Astrophysics ,Physics ,Degree (graph theory) ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Supernova ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::Earth and Planetary Astrophysics ,Mass fraction ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
X-ray luminosity, temperature, gas mass, total mass, and their scaling relations are derived for 94 early-type galaxies using archival $Chandra$ X-ray Observatory observations. Consistent with earlier studies, the scaling relations, $L_X \propto T^{4.5\pm0.2}$, $M \propto T^{2.4\pm0.2}$, and $L_X \propto M^{2.8\pm0.3}$, are significantly steeper than expected from self similarity. This steepening indicates that their atmospheres are heated above the level expected from gravitational infall alone. Energetic feedback from nuclear black holes and supernova explosions are likely heating agents. The tight $L_X - T$ correlation for low-luminosities systems (i.e., below 10$^{40}$ erg/s) are at variance with hydrodynamical simulations which generally predict higher temperatures for low luminosity galaxies. We also investigate the relationship between total mass and pressure, $Y_X = M_g \times T$, finding $M \propto Y_{X}^{0.45\pm0.04}$. We explore the gas mass to total mass fraction in early-type galaxies and find a range of $0.1-1.0\%$. We find no correlation between the gas-to-total mass fraction with temperature or total mass. Higher stellar velocity dispersions and higher metallicities are found in hotter, brighter, and more massive atmospheres. X-ray core radii derived from $\beta$-model fitting are used to characterize the degree of core and cuspiness of hot atmospheres., Comment: 19 pages, 8 figures, accepted for publication in The Astrophysical Journal
- Published
- 2018
- Full Text
- View/download PDF
27. A 10^10 solar mass flow of molecular gas in the A1835 brightest cluster galaxy
- Author
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Stephen Hamer, C. C. Kirkpatrick, F. Combes, P. Salomé, G. M. Voit, E. Egami, P. E. J. Nulsen, Joel N. Bregman, Christopher P. O'Dea, Stefi A. Baum, A. C. Edge, J. B. R. Oonk, Norm Murray, Grant R. Tremblay, Robert Main, Andrew C. Fabian, Brian R. McNamara, Megan Donahue, Helen Russell, and A. N. Vantyghem
- Subjects
Physics ,Solar mass ,active [Galaxies] ,Star formation ,jets and outflows [ISM] ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy and Astrophysics ,Radius ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,clusters: general [Galaxies] ,star formation [Galaxies] ,molecules. [ISM] ,Stars ,13. Climate action ,Space and Planetary Science ,Bipolar outflow ,Elliptical galaxy ,Outflow ,clusters: individual (A1835) [Galaxies] ,Brightest cluster galaxy ,Astrophysics::Galaxy Astrophysics - Abstract
We report ALMA Early Science observations of the A1835 brightest cluster galaxy (BCG) in the CO (3-2) and CO (1-0) emission lines. We detect 5 × 1010 M ☉ of molecular gas within 10 kpc of the BCG. Its ensemble velocity profile width of ~130 km s–1 FWHM is too narrow for the molecular clouds to be supported in the galaxy by dynamic pressure. The gas may instead be supported in a rotating, turbulent disk oriented nearly face-on. Roughly 1010 M ☉ of molecular gas is projected 3-10 kpc to the northwest and to the east of the nucleus with line-of-sight velocities lying between –250 km s–1 and +480 km s–1 with respect to the systemic velocity. The high-velocity gas may be either inflowing or outflowing. However, the absence of high-velocity gas toward the nucleus that would be expected in a steady inflow, and its bipolar distribution on either side of the nucleus, are more naturally explained as outflow. Star formation and radiation from the active galactic nucleus (AGN) are both incapable of driving an outflow of this magnitude. The location of the high-velocity gas projected behind buoyantly rising X-ray cavities and favorable energetics suggest an outflow driven by the radio AGN. If so, the molecular outflow may be associated with a hot outflow on larger scales reported by Kirkpatrick and colleagues. The molecular gas flow rate of approximately 200 M ☉ yr–1 is comparable to the star formation rate of 100-180 M ☉ yr–1 in the central disk. How radio bubbles would lift dense molecular gas in their updrafts, how much gas will be lost to the BCG, and how much will return to fuel future star formation and AGN activity are poorly understood. Our results imply that radio-mechanical (radio-mode) feedback not only heats hot atmospheres surrounding elliptical galaxies and BCGs, but it is able to sweep higher density molecular gas away from their centers.
- Published
- 2014
28. Cycling of the powerful AGN in MS 0735.6+7421 and the duty cycle of radio AGN in Clusters
- Author
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Helen Russell, Henk Hoekstra, Myriam Gitti, Michael W. Wise, Brian R. McNamara, A. N. Vantyghem, Paul Nulsen, R. A. Main, Vantyghem A. N., McNamara B. R., Russell H. R., Main R. A., Nulsen P. E. J., Wise M. W., Hoekstra H., and Gitti M.
- Subjects
galaxies: clusters: intracluster medium ,galaxies: jet ,Astrophysics::High Energy Astrophysical Phenomena ,galaxies: active ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Atmosphere ,symbols.namesake ,Intracluster medium ,Surface brightness ,Astrophysics::Galaxy Astrophysics ,Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Jet (fluid) ,Shock (fluid dynamics) ,Star formation ,Astronomy ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,galaxies: clusters: individual: MS 0735.6+7421 ,Mach number ,Space and Planetary Science ,X-rays: galaxies: clusters ,Astrophysics of Galaxies (astro-ph.GA) ,symbols ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
We present an analysis of deep Chandra X-ray observations of the galaxy cluster MS 0735.6+7421, which hosts the most energetic radio AGN known. Our analysis has revealed two cavities in its hot atmosphere with diameters of 200-240 kpc. The total cavity enthalpy, mean age, and mean jet power are $9\times 10^{61}$ erg, $1.6\times 10^{8}$ yr, and $1.7\times 10^{46}$ erg/s, respectively. The cavities are surrounded by nearly continuous temperature and surface brightness discontinuities associated with an elliptical shock front of Mach number 1.26 (1.17-1.30) and age of $1.1\times 10^{8}$ yr. The shock has injected at least $4\times 10^{61}$ erg into the hot atmosphere at a rate of $1.1\times 10^{46}$ erg/s. A second pair of cavities and possibly a second shock front are located along the radio jets, indicating that the AGN power has declined by a factor of 30 over the past 100 Myr. The multiphase atmosphere surrounding the central galaxy is cooling at a rate of 36 Msun/yr, but does not fuel star formation at an appreciable rate. In addition to heating, entrainment in the radio jet may be depleting the nucleus of fuel and preventing gas from condensing out of the intracluster medium. Finally, we examine the mean time intervals between AGN outbursts in systems with multiple generations of X-ray cavities. We find that, like MS0735, their AGN rejuvenate on a timescale that is approximately 1/3 of their mean central cooling timescales, indicating that jet heating is outpacing cooling in these systems., Comment: 15 pages, 15 figures. Accepted for publication in MNRAS on May 21, 2014
- Published
- 2014
- Full Text
- View/download PDF
29. An Enormous Molecular Gas Flow in the RX J0821+0752 Galaxy Cluster.
- Author
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A. N. Vantyghem, B. R. McNamara, H. R. Russell, A. C. Edge, P. E. J. Nulsen, F. Combes, A. C. Fabian, M. McDonald, and P. Salomé
- Subjects
- *
GAS flow , *GALAXY clusters , *ACTIVE galaxies , *INTERSTELLAR medium , *INTERSTELLAR gases , *CARBON oxides , *COLD gases , *SLOSHING (Hydrodynamics) - Abstract
We present recent Chandra X-ray observations of the RX J0821.0+0752 galaxy cluster, in addition to ALMA observations of the CO(1–0) and CO(3–2) line emission tracing the molecular gas in its central galaxy. All of the CO line emission, originating from a molecular gas reservoir, is located several kiloparsecs away from the nucleus of the central galaxy. The cold gas is concentrated into two main clumps surrounded by a diffuse envelope. They form a wide filament coincident with a plume of bright X-ray emission emanating from the cluster core. This plume encompasses a putative X-ray cavity that is only large enough to have uplifted a small percent of the molecular gas. Unlike other brightest cluster galaxies, stimulated cooling, where X-ray cavities lift low-entropy cluster gas until it becomes thermally unstable, cannot have produced the observed gas reservoir. Instead, the molecular gas has likely formed as a result of sloshing motions in the intracluster medium induced by a nearby galaxy. Sloshing can emulate uplift by dislodging gas from the galactic center. This gas has the shortest cooling time, so it will condense if disrupted for long enough. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
30. Molecular Gas Filaments and Star-forming Knots Beneath an X-Ray Cavity in RXC J1504–0248.
- Author
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A. N. Vantyghem, B. R. McNamara, H. R. Russell, A. C. Edge, P. E. J. Nulsen, F. Combes, A. C. Fabian, M. McDonald, and P. Salomé
- Subjects
- *
STAR formation , *ASTRONOMICAL photometry , *CONDENSATION , *X-rays , *GALACTIC nuclei - Abstract
We present recent ALMA observations of the CO (1–0) and CO (3–2) emission lines in the brightest cluster galaxy of RXC J1504.1−0248, which is one of the most extreme cool core clusters known. The central galaxy contains of molecular gas. The molecular gas morphology is complex and disturbed, showing no evidence for a rotationally supported structure in equilibrium. A total of 80% of the gas is situated within the central 5 kpc of the galactic center, while the remaining gas is located in a 20 kpc long filament. The cold gas has likely condensed out of the hot atmosphere. The filament is oriented along the edge of a putative X-ray cavity, suggesting that active galactic nucleus activity has stimulated condensation. This is energetically feasible, although the morphology is not as conclusive as systems whose molecular filaments trail directly behind buoyant radio bubbles. The velocity gradient along the filament is smooth and shallow. It is only consistent with freefall if it lies within 20° of the plane of the sky. The abundance of clusters with comparably low velocities suggests that the filament is not freefalling. Both the central gas and filamentary gas are coincident with bright UV emission from ongoing star formation. Star formation near the cluster core is consistent with the Kennicutt–Schmidt law. The filament exhibits increased star formation surface densities, possibly resulting from either the consumption of a finite molecular gas supply or spatial variations in the CO-to-H2 conversion factor. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
31. A Universal Entropy Profile for the Hot Atmospheres of Galaxies and Clusters within R 2500.
- Author
-
Iu. V. Babyk, B. R. McNamara, P. E. J. Nulsen, H. R. Russell, A. N. Vantyghem, M. T. Hogan, and F. A. Pulido
- Subjects
GALAXY clusters ,ENTROPY ,SPIRAL galaxies ,GALACTIC halos ,STELLAR mass ,STAR formation - Abstract
We present atmospheric gas entropy profiles for 40 early-type galaxies and 110 clusters spanning several decades of halo mass, atmospheric gas mass, radio jet power, and galaxy type. We show that within ∼0.1R
2500 the entropy profiles of low-mass systems, including ellipticals, brightest cluster galaxies, and spiral galaxies, scale approximately as K ∝ R2/3 . Beyond ∼0.1R2500 entropy profiles are slightly shallower than the K ∝ R1.1 profile expected from gravitational collapse alone, indicating that heating by active galactic nuclei (AGN) feedback extends well beyond the central galaxy. We show that the K ∝ R2/3 entropy profile shape indicates that thermally unstable cooling is balanced by heating where the inner cooling and free-fall timescales approach a constant ratio. Hot atmospheres of elliptical galaxies have a higher rate of heating per gas particle compared to those of central cluster galaxies. This excess heating may explain why some central cluster galaxies are forming stars while most early-type galaxies have experienced no significant star formation for billions of years. We show that the entropy profiles of six lenticular and spiral galaxies follow the R2/3 form. The continuity between central galaxies in clusters, giant ellipticals, and spirals suggests perhaps that processes heating the atmospheres of elliptical and brightest cluster galaxies are also active in spiral galaxies. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
32. X-Ray Scaling Relations of Early-type Galaxies.
- Author
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A. N. Vantyghem, F. A. Pulido, Iu. V. Babyk, B. R. McNamara, M. T. Hogan, P. E. J. Nulsen, H. R. Russell, and A. C. Edge
- Subjects
- *
GALAXIES , *ELLIPTICAL galaxies , *GALACTIC X-ray sources , *SUPERNOVAE , *BLACK holes - Abstract
X-ray luminosity, temperature, gas mass, total mass, and their scaling relations are derived for 94 early-type galaxies (ETGs) using archival Chandra X-ray Observatory observations. Consistent with earlier studies, the scaling relations, LX ∝ T4.5±0.2, M ∝ T2.4±0.2, and LX ∝ M2.8±0.3, are significantly steeper than expected from self-similarity. This steepening indicates that their atmospheres are heated above the level expected from gravitational infall alone. Energetic feedback from nuclear black holes and supernova explosions are likely heating agents. The tight LX–T correlation for low-luminosity systems (i.e., below 1040 erg s−1) are at variance with hydrodynamical simulations, which generally predict higher temperatures for low-luminosity galaxies. We also investigate the relationship between total mass and pressure, YX = Mg × T, finding . We explore the gas mass to total mass fraction in ETGs and find a range of 0.1%–1.0%. We find no correlation between the gas-to-total mass fraction with temperature or total mass. Higher stellar velocity dispersions and higher metallicities are found in hotter, brighter, and more massive atmospheres. X-ray core radii derived from β-model fitting are used to characterize the degree of core and cuspiness of hot atmospheres. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
33. The Origin of Molecular Clouds in Central Galaxies.
- Author
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F. A. Pulido, B. R. McNamara, A. C. Edge, M. T. Hogan, A. N. Vantyghem, H. R. Russell, P. E. J. Nulsen, I. Babyk, and P. Salomé
- Subjects
MOLECULAR clouds ,STAR formation ,SOLAR wind ,ASTRONOMICAL observations ,ENTROPY - Abstract
We present an analysis of 55 central galaxies in clusters and groups with molecular gas masses and star formation rates lying between and 0.5 and 270 , respectively. Molecular gas mass is correlated with star formation rate, Hα line luminosity, and central atmospheric gas density. Molecular gas is detected only when the central cooling time or entropy index of the hot atmosphere falls below ∼1 Gyr or ∼35 keV cm
2 , respectively, at a (resolved) radius of 10 kpc. These correlations indicate that the molecular gas condensed from hot atmospheres surrounding the central galaxies. We explore the origins of thermally unstable cooling by evaluating whether molecular gas becomes prevalent when the minimum of the cooling to free-fall time ratio () falls below ∼10. We find that (1) molecular gas-rich systems instead lie between , where corresponds approximately to cooling time and entropy thresholds of 1 Gyr and , respectively; (2) ) is uncorrelated with molecular gas mass and jet power; and (3) the narrow range can be explained by an observational selection effect, although a real physical effect cannot be excluded. These results and the absence of isentropic cores in cluster atmospheres are in tension with models that assume thermal instability ensues from linear density perturbations in hot atmospheres when . Some of the molecular gas may instead have condensed from atmospheric gas lifted outward by buoyantly rising X-ray bubbles or by dynamically induced uplift (e.g., mergers, sloshing). [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
34. The Onset of Thermally Unstable Cooling from the Hot Atmospheres of Giant Galaxies in Clusters: Constraints on Feedback Models.
- Author
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M. T. Hogan, B. R. McNamara, F. A. Pulido, P. E. J. Nulsen, A. N. Vantyghem, H. R. Russell, A. C. Edge, Iu. Babyk, R. A. Main, and M. McDonald
- Subjects
ACTIVE galaxies ,GALAXY clusters ,INTERSTELLAR medium ,STELLAR luminosity function ,STAR formation - Abstract
We present accurate mass and thermodynamic profiles for 57 galaxy clusters observed with the Chandra X-ray Observatory. We investigate the effects of local gravitational acceleration in central cluster galaxies, and explore the role of the local free-fall time () in thermally unstable cooling. We find that the radially averaged cooling time () is as effective an indicator of cold gas, traced through its nebular emission, as the ratio /. Therefore, primarily governs the onset of thermally unstable cooling in hot atmospheres. The location of the minimum /, a thermodynamic parameter that many simulations suggest is key in driving thermal instability, is unresolved in most systems. Consequently, selection effects bias the value and reduce the observed range in measured / minima. The entropy profiles of cool-core clusters are characterized by broken power laws down to our resolution limit, with no indication of isentropic cores. We show, for the first time, that mass isothermality and the entropy profile slope imply a floor in / profiles within central galaxies. No significant departures of / below 10 are found. This is inconsistent with models that assume thermally unstable cooling ensues from linear perturbations at or near this threshold. We find that the inner cooling times of cluster atmospheres are resilient to active galactic nucleus (AGN)-driven change, suggesting gentle coupling between radio jets and atmospheric gas. Our analysis is consistent with models in which nonlinear perturbations, perhaps seeded by AGN-driven uplift of partially cooled material, lead to cold gas condensation. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
35. A 13CO Detection in a Brightest Cluster Galaxy.
- Author
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A. N. Vantyghem, B. R. McNamara, A. C. Edge, F. Combes, H. R. Russell, A. C. Fabian, M. T. Hogan, M. McDonald, P. E. J. Nulsen, and P. Salomé
- Subjects
- *
MOLECULAR clouds , *THERMODYNAMICS , *VELOCITY , *CARBON monoxide spectra , *HYDROGEN spectra , *GALAXY clusters - Abstract
We present ALMA Cycle 4 observations of CO(1-0), CO(3-2), and 13CO(3-2) line emission in the brightest cluster galaxy (BCG) of RXJ0821+0752. This is one of the first detections of 13CO line emission in a galaxy cluster. Half of the CO(3-2) line emission originates from two clumps of molecular gas that are spatially offset from the galactic center. These clumps are surrounded by diffuse emission that extends 8 kpc in length. The detected 13CO emission is confined entirely to the two bright clumps, with any emission outside of this region lying below our detection threshold. Two distinct velocity components with similar integrated fluxes are detected in the 12CO spectra. The narrower component (60 km s−1 FWHM) is consistent in both velocity centroid and linewidth with 13CO(3-2) emission, while the broader (130–160 km s−1), slightly blueshifted wing has no associated 13CO(3-2) emission. A simple local thermodynamic model indicates that the 13CO emission traces 2.1 × 109M⊙ of molecular gas. Isolating the 12CO velocity component that accompanies the 13CO emission yields a CO-to-H2 conversion factor of αCO = 2.3 M⊙ (K km s−1)−1, which is a factor of two lower than the Galactic value. Adopting the Galactic CO-to-H2 conversion factor in BCGs may therefore overestimate their molecular gas masses by a factor of two. This is within the object-to-object scatter from extragalactic sources, so calibrations in a larger sample of clusters are necessary in order to confirm a sub-Galactic conversion factor. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
36. MOLECULAR GAS ALONG A BRIGHT Hα FILAMENT IN 2A 0335+096 REVEALED BY ALMA.
- Author
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A. N. Vantyghem, B. R. McNamara, M. T. Hogan, M. Donahue, G. M. Voit, R. A. Main, N. W. Murray, I. J Parrish, R. W. O'Connell, J. B. R. Oonk, J. S. Sanders, G. Tremblay, H. R. Russell, A. C. Fabian, A. C. Edge, P. E. J. Nulsen, P. Salomé, F. Combes, S. A. Baum, and C. P. O'Dea
- Subjects
- *
GALAXIES , *GALAXY clusters , *KINEMATICS , *DYNAMICS , *REDSHIFT - Abstract
We present ALMA CO(1–0) and CO(3–2) observations of the brightest cluster galaxy (BCG) in the 2A 0335+096 galaxy cluster (z = 0.0346). The total molecular gas mass of 1.13 ± 0.15 × 109M⊙ is divided into two components: a nuclear region and a 7 kpc long dusty filament. The central molecular gas component accounts for 3.2 ± 0.4 × 108M⊙ of the total supply of cold gas. Instead of forming a rotationally supported ring or disk, it is composed of two distinct, blueshifted clumps south of the nucleus and a series of low-significance redshifted clumps extending toward a nearby companion galaxy. The velocity of the redshifted clouds increases with radius to a value consistent with the companion galaxy, suggesting that an interaction between these galaxies <20 Myr ago disrupted a pre-existing molecular gas reservoir within the BCG. Most of the molecular gas, 7.8 ± 0.9 × 108M⊙, is located in the filament. The CO emission is co-spatial with a 104 K emission-line nebula and soft X-rays from 0.5 keV gas, indicating that the molecular gas has cooled out of the intracluster medium over a period of 25–100 Myr. The filament trails an X-ray cavity, suggesting that the gas has cooled from low-entropy gas that has been lifted out of the cluster core and become thermally unstable. We are unable to distinguish between inflow and outflow along the filament with the present data. Cloud velocities along the filament are consistent with gravitational free-fall near the plane of the sky, although their increasing blueshifts with radius are consistent with outflow. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
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